Body fluid collecting device

ABSTRACT

A body fluid collecting device which is easy to operate to collect body fluid and which is capable of detecting specific components in body fluid with a small amount of sample includes a sensor to detect a prescribed component in the body fluid, and a first supporter to support the vicinity of the measuring part of the sensor and a second supporter to support the sensor at a place closer to the proximal end than the first supporter. The first and second supporters form between them a non-contact space, wherein the first supporter has at its proximal end a concave that communicates with the non-contact space.

This application claims priority on Japanese patent application Nos.2002-192773 and 2002-192774, the entire contents of which are herebyincorporated by reference. In addition, the entire content of literaturecited in this specification are incorporated by reference.

TECHNICAL FIELD

The present invention relates to a body fluid collecting device to bemounted on an apparatus for measuring components, such an apparatus formeasuring the blood glucose level.

BACKGROUND ART

There have been proposed several methods for determining variouscomponents in blood, particularly by analyzing the reaction productsresulting from reaction between specific components in blood andspecific enzymes. Measurement of blood glucose level is important tomonitor the patient's status. It has been recommended that the patientmeasures his own blood glucose level every day by himself. In view ofthe recent increasing number of diabetics, there is a growing demand fora simple method and means of measuring blood glucose level with aminimum of pain.

Measurements of blood glucose level are usually accomplished byutilizing the enzymatic reaction to oxidize glucose. The enzymes forthis purpose are glucose oxidase, glucose dehydrogenase, and the like.At present, colorimetric and electrical methods are used fordetermination of blood glucose level. The former method consists ofattaching an indicator paper to a measurement device, introducing bloodsample to the indicator paper which develops a color upon reaction withblood glucose and optically measuring the thus developed color. Thelatter method consists of measuring the amount of current flowing acrosselectrodes in contact with the product resulting from enzymaticreaction.

What is essential for these methods is to collect blood samples foranalysis. Before measurement, the patient has to collect his own blood.A common way to achieve this object is by sticking the patient's skin(that of the fingertip, for example) with a sticking device providedwith a sticking needle and then squeezing out blood by pressing withfingers the surrounding of the point of sticking.

Unfortunately, the conventional optical measuring method using theindicator paper requires a comparatively large amount of blood and hencenecessitates sticking the needle deep into the skin. This causes pain tothe patient and intimidates many patients into giving up a selfmeasurement of blood glucose level. This holds true for the electricalmeasuring method which also requires as much blood as the calorimetricmethod.

The conventional sensor used to electrically measure blood glucose levelis usually composed of an insulating substrate or sheet, carbon or metalelectrodes formed thereon by screen printing or the like, and a layerthat absorbs blood dropped thereon. The layer contains an enzyme,electron acceptor, and electrolyte for pH adjustment. Many of thesensors are in the form of thin strip chip. In these sensors, the layerto absorb blood is formed at the distal end or side of the strip, sothat it is given a blood sample directly. This structure presentsdifficulties in accurately placing a blood drop or tends to cause afailure.

If the sensor in strip form is integrated with a sticking needle, thenthe resulting device obviates the necessity of mounting the stickingneedle and the sensor separately. This will simplify operation andimprove usability. This idea, however, poses a problem of making itdifficult to delicately adjust the sticking depth, which is the fatalcause for pain due to sticking.

Moreover, the device of integral type is complex in structure and tendsto waste blood infiltrating into gaps between constituent members.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a body fluidcollecting device which is easy to operate to collect body fluid andwhich is capable of detecting specific components in body fluid with asmall amount of sample. It is another object of the present invention toprovide a body fluid collecting device of the type integral with asticking needle, which permits easy control of sticking depth. It isstill another object of the present invention to provide a body fluidcollecting device of the type integral with a sticking needle, whichsurely detects specific components in body fluid.

The above-mentioned objects are achieved by the invention defined in thefollowing paragraphs (1) to (27).

(1) A body fluid collecting device having a sensor to detect aprescribed component in the body fluid, characterized in that

the sensor has at its distal end a measuring part capable of holding thebody fluid, and

the body fluid collecting device has a first supporter to support thevicinity of the measuring part of the sensor and a second supporter tosupport the sensor at a place closer to the proximal end than the firstsupporter and also has means to prevent the body fluid from infiltratinginto other parts than the measuring part.

(2) A body fluid collecting device having a sensor to detect aprescribed component in the body fluid, characterized in that

the sensor has at its distal end a measuring part capable of holding thebody fluid, and

the body fluid collecting device has a first supporter to support thevicinity of the measuring part of the sensor and a second supporter tosupport the sensor at a place closer to the proximal end than the firstsupporter, with the first and second supporters forming between them anon-contact space in which the surface of the sensor does notsubstantially come into contact with the inside of the body fluidcollecting device.

(3) The body fluid collecting device as defined in Paragraph (2),wherein the first supporter has at its proximal end a concave thatcommunicates with the non-contact space.

(4) The body fluid collecting device as defined in Paragraph (3),wherein the concave is a notch formed by cutting part of the firstsupporter.

(5) The body fluid collecting device as defined in any of Paragraphs (2)to (4), wherein the sensor is bent or curved in the non-contact space.

(6) The body fluid collecting device as defined in any of Paragraphs (1)to (5), wherein the first supporter is arranged closer to the centralaxis of the body fluid collecting device than the second supporter.

(7) The body fluid collecting device as defined in any of Paragraphs (1)to (6), which further has a body fluid duct which communicates with thefirst supporter and introduces the body fluid into the measuring part.

(8) The body fluid collecting device as defined in Paragraph (7),wherein the body fluid duct has a volume which is 0.5 to 2 times thevolume of the measuring part.

(9) The body fluid collecting device as defined in Paragraph (7) or (8),wherein the body fluid duct is 0.1 to 10 mm in length and 0.1 to 3 mm ininside diameter.

(10) The body fluid collecting device as defined in any of Paragraphs(7) to (9), wherein the measuring part is inclined with respect to thelengthwise direction of the body fluid duct and is positioned in thevicinity of the outlet opening of the body fluid duct.

(11) The body fluid collecting device as defined in any of Paragraphs(7) to (10), which further has a guide that projects from the distal endof the body fluid collecting device and introduces the body fluid intothe inlet opening of the body fluid duct,

the guide being formed such that the distance from the distal endthereof to the inlet opening of the body fluid duct is 1 to 10 mm.

(12) The body fluid collecting device as defined in any of Paragraphs(1) to (11), wherein the sensor electrically detects the prescribedcomponent in the body fluid by contact with the body fluid.

(13) A body fluid collecting device of the type integral with a stickingneedle which includes:

a needle accommodating part provided with a sticking needle which sticksthe skin to bleed body fluid,

a sensor to detect prescribed components in the body fluid, and

a sensor holder which is mounted on the distal end of the needleaccommodating part and which supports the sensor between the needleaccommodating part and the sensor holder.

(14) The body fluid collecting device of the type integral with asticking needle as defined in Paragraph (13), wherein the sensor has itsdistal end side curved or inclined toward the central axis of thesticking needle.

(15) The body fluid collecting device of the type integral with asticking needle as defined in Paragraph (13) or (14), wherein the sensorhas its proximal end side held between the needle accommodating part andthe sensor holder.

(16) The body fluid collecting device of the type integral with asticking needle as defined in any of Paragraphs (13) to (15), whereinthe sensor is capable of holding the body fluid in its distal end and isprovided with a measuring part to determine the prescribed components.

(17) The body fluid collecting device of the type integral with asticking needle as defined in Paragraph (16), wherein the sensor holderhas a body fluid duct which introduces the body fluid into the measuringpart.

(18) The body fluid collecting device of the type integral with asticking needle as defined in Paragraph (17), wherein the measuring partis inclined with respect to the lengthwise direction of the body fluidduct and is positioned in the vicinity of the outlet opening of the bodyfluid duct.

(19) The body fluid collecting device of the type integral with asticking needle as defined in Paragraph (17) or (18), wherein the sensorholder has a guide that projects from the distal end thereof andintroduces the body fluid into the inlet opening of the body fluid duct,so that the sticking needle sticks into the skin while the distal end ofthe guide is in contact with the skin.

(20) The body fluid collecting device of the type integral with asticking needle as defined in any of Paragraphs (13) to (19), whereinthe sensor holder is fixed by fitting to the needle accommodating part.

(21) The body fluid collecting device of the type integral with asticking needle as defined in any of Paragraphs (13) to (20), whichfurther has means to position the sensor holder with respect to thelengthwise direction of the needle accommodating part.

(22) The body fluid collecting device of the type integral with asticking needle as defined in Paragraph (21), wherein the positioningmeans is a step that is formed on the outside midway in the lengthwisedirection of the needle accommodating part such that the proximal end ofthe sensor holder comes into contact with it.

(23) The body fluid collecting device of the type integral with asticking needle as defined in any of Paragraphs (13) to (22), whereinthe sensor holder has at least the distal end thereof made substantiallytransparent.

(24) The body fluid collecting device of the type integral with asticking needle as defined in any of Paragraphs (13) to (23), which isassembled after the needle accommodating part has undergonesterilization in such a state that its opening is sealed with amembrane, the opening being formed at the distal end of the needleaccommodating part such that the sticking needle can pass through it.

(25) The body fluid collecting device of the type integral with asticking needle as defined in Paragraph (24), wherein the needleaccommodating part keeps its inside sterilized until the time of use.

(26) The body fluid collecting device of the type integral with asticking needle as defined in any of Paragraphs (13) to (25), whichassumes approximately a rectangular solid in its entire shape.

(27) The body fluid collecting device of the type integral with asticking needle as defined in any of Paragraphs (13) to (26), whereinthe sensor electrically detects the prescribed component in the bodyfluid by contact with the body fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the body fluid collecting deviceaccording to the first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the body fluid collectingdevice shown in FIG. 1.

FIG. 3 is a sectional view taken along the line A-A in FIG. 1.

FIG. 4 is a bottom view of the distal end of the sensor holder installedin the fluid body collecting device shown in FIG. 1.

FIG. 5 is a longitudinal sectional view showing one example of thestructure of the sealing member.

FIG. 6 is a longitudinal sectional view showing another example of thestructure of the sealing member.

FIG. 7 is a longitudinal sectional view showing the structure of the tipof the body fluid collecting device according to the second embodimentof the present invention.

FIG. 8 is a schematic exploded perspective view of the componentmeasuring apparatus on which is mounted the body fluid collecting deviceaccording to the present invention.

FIG. 9 is a schematic diagram (partly in section) showing how thecomponent measuring apparatus shown in FIG. 8 is made up of a housing,sticking means, and measuring means.

FIG. 10 is a schematic diagram (partly in section) showing how thecomponent measuring apparatus shown in FIG. 8 is made up of a housing,sticking means, and measuring means.

BEST MODE FOR CARRYING OUT THE INVENTION

<Component Measuring Apparatus>

The body fluid collecting device according to the present invention ismounted on a device for measuring components when it is in use. Thelatter will be explained first with reference to FIGS. 8 to 10. In thefollowing description, it is assumed that the apparatus is intended tocollect body fluid (typically blood) through the skin and measure(detect) specific components in the collected body fluid.

It is desirable to collect body fluid through the skin of the finger;however, it is also possible to collect body fluid through the skin ofthe hand (palm, back, or side), arm, thigh, or ear lobe. In thefollowing description, it is assumed that the apparatus is so designedas to collect body fluid by sticking the fingertip.

FIG. 8 is a schematic exploded perspective view of the componentmeasuring apparatus on which is mounted the body fluid collecting deviceaccording to the present invention. FIGS. 9 and 10 are schematicdiagrams (partly in section) showing how the component measuringapparatus shown in FIG. 8 is made up of a housing, sticking means, andmeasuring means. Incidentally, conventions are adopted as follows in thefollowing description. “Proximal end”, “distal end”, “up”, “down”represent respectively the right side, the left side, the upper side,and the lower side in FIGS. 8 to 10.

The component measuring apparatus (or the blood component measuringapparatus) 100 shown in FIG. 8 includes a main body 200, a housing 500holding a sticking means 400, a measuring means 700, a power source(batteries) 900, a circuit board 110 and a control means 111 mountedthereon, and a display unit 112. The measuring means 700 is designed tomeasure (detect) a specific component (typically glucose in thisembodiment) in the collected blood (body fluid). The component measuringapparatus 100 is designed such that the body fluid collecting device 1according to the present invention is fixed in the distal end of thehousing 500.

The constituents of the apparatus 100 will be described one by one inthe following.

The main body 200 includes a casing 210 and a lid 220 and contains theconstituents mentioned above.

The wall 211 at the distal end of the casing 210 has an approximately byrectangular opening 212 (conforming to the cross section of the bodyfluid collecting device 1 mentioned later) penetrating the wall of thecasing 210. The body fluid collecting device 1 is fitted into the distalend of the housing 500 through the opening 212.

In the lid 220, an opening (window) 221 closed by a transparent sheet isformed, and penetrates the lid 220.

The display unit 112 is installed at that part in the main body 200which corresponds to the window 221. Thus the window 221 permits theuser to see through it various kinds of information displayed on thedisplay unit 112.

The display unit 112 consists of liquid crystal display elements (LCDs)or the like. It displays such information as power on/off, power sourcevoltage (remaining capacity), measured values, date and time ofmeasurement, error indication, and operation guidance.

On the lid 220 is arranged a control button 222, the depressing of whichactuates the sticking means 400 mentioned later.

The control means 111 controls the actions of each part in the componentmeasuring apparatus 100. It is also provided with an arithmetic sectionto calculate the blood glucose level in response to signals from themeasuring means 700.

The battery 900 supplies the control means 111, the display unit 112,and the measuring means 700 with electric power for their operationthrough electric connections.

The casing 210 has an opening 212 which corresponds to the distalopening 501 of the housing 500.

As shown in FIGS. 9 and 10, the housing 500 is a cylindrical memberhaving a bottom 510 and an internal space 520 for accommodation.

At the distal end of the housing 500, a holder 530 which has an internalshape formed corresponding to an external shape of the body fluidcollecting device 1 is formed. Into the holder 530, the body fluidcollecting device 1 snugly fits.

The sticking means 400 is held in the internal space 520 in the proximalside of the holder 530. The sticking means 400 is so designed as to movedistally the sticking needle 4 which is held by the needle holder 411.The sticking needle 4 has a needle body 41 having a sharp needle point,which sticks into the skin of the fingertip F.

The sticking means 400 includes a plunger 410, a coil spring 420 to urgethe plunger 410 toward the distal end, and a coil spring 430 to urge theplunger 410 toward the proximal end.

The plunger 410 has an integrally formed cup-like needle holder 411 atits distal end. This needle holder 411 detachably holds the fitting part421 of the sticking needle 4.

The plunger 410 has an integrally formed elastic piece 412, which candeform elastically, extending from its proximal end. This elastic piece412 has a locking part 413 projecting from its distal end. It deflectsup and down about its proximal end so that the locking part 413 moves upand down, as shown in FIGS. 9 and 10.

The top of the locking part 413 is in contact with the inside of thehousing 500 due to the elastic force of the elastic piece 412 before thebody fluid collecting device 1 is held in the housing 500 (or before thesticking needle 4 is held by the needle holder 411 of the plunger 410),as shown in FIG. 9. On the other hand, after the body fluid collectingdevice 1 has been held in the housing 500 (or after the sticking needle4 has been held by the needle holder 411 of the plunger 410), thelocking part 413 enters the opening 570 formed in the side wall of thehousing 500 and locked at the edge of the opening 570, as shown in FIG.10. Thus the plunger 410 is restrained from moving forward.

The coil spring (for sticking) 420 extends from the plunger 410 towardthe proximal end side, so that its both ends are in contact with theplunger 410 and the wall 510. On the other hand, the coil spring (forreturn) 430 extends from the distal end of the plunger 410, so that itsboth ends are in contact with the plunger 410 and the holder 530.

As shown in FIGS. 9 and 10, outside the housing 500 is an unlocking part223, which pushes the locking part 413 toward the internal space 520 (orin the direction of arrow). This unlocking part 223 is actuated as thecontrol button 222 (mentioned above) is depressed.

While the locking part 413 is in engagement with the edge of the opening570 (as shown in FIG. 10), the coil spring 420 is compressed to urge theplunger 410 toward the distal end. As the unlocking part 223 is moved inthe direction of arrow and the locking part 413 is unlocked (as shown inFIG. 10), the coil spring 420 extends to move the plunger 410 toward thedistal end. As the result, the sticking needle 4 is moved toward thedistal end, so that the tip of the needle body 41 sticks into the skinof the fingertip F. In this state, the coil spring 430 is compressed.

Then, the coil spring 430 pushes back the plunger 410 toward theproximal end. The plunger 410 reciprocates (or repeatedly moves towardthe distal end and toward the proximal end) due to elastic force appliedby the coil springs 420 and 430. It eventually comes to rest at aposition where the force of the coil spring 420 balances with that ofthe coil spring 430.

While the plunger 410 is at rest, the tip of the needle body 41 (fixedto the sticking needle 4) is accommodated in the body fluid collectingdevice 1.

The measuring means 700 includes a voltage regulating circuit 710 (whichapplies a prescribed voltage to the sensor 5 of the body fluidcollecting device 1), a current measuring device 720 for measuring acurrent value, and contact points 731 and 732 (which come into contactwith the electrodes 52 a and 52 b of the sensor 5).

The contact point 731 is electrically connected to the battery 900through the voltage regulating circuit 710, and the contact point 732 iselectrically connected to the battery 900 through the current measuringdevice 720.

The measuring means 700 measures (detects), by means of the currentmeasuring device 720, change in the current which the sensor 5 outputsaccording to the amount of glucose in blood, and it sends the detectedsignals to the control means 111.

The control means (arithmetic unit) 111 performs prescribed computing inresponse to input signals and also optionally performs calibration,thereby determining the blood glucose level. The thus determined bloodglucose level is displayed on the display unit 112.

On the component measuring apparatus 100 mentioned above is mounted thebody fluid collecting device 1 according to the present invention.

<Body Fluid Collecting Device>

A detailed description is given below of the body fluid collectingdevice according to the present invention.

First Embodiment

The first embodiment of the present invention covers the body fluidcollecting device integral with the sticking needle.

FIG. 1 is a perspective view showing the body fluid collecting deviceaccording to the first embodiment of the present invention. FIG. 2 is anexploded perspective view of the body fluid collecting device shown inFIG. 1. FIG. 3 is a sectional view taken along the line A-A in FIG. 1.FIG. 4 is a bottom view of the distal end of the sensor holder installedin the fluid body collecting device shown in FIG. 1. FIGS. 5 and 6 arelongitudinal sectional views showing the examples of structure of-thesealing member. Incidentally, conventions are adopted as follows in thefollowing description. “Proximal end”, “distal end”, up and “down”represent respectively the right side, the left side, the upper side,and the lower side.

The body fluid collecting device 1 shown in FIG. 1 and other has aneedle accommodating part 2, a sensor 5, and a sensor holder 6.

Descriptions will be made sequentially of the constituents of the bodyfluid collecting device 1.

The needle accommodating section (sticking needle unit) 2 includes thecasing 3 and the sticking needle 4 which is accommodated in the casing 3such that it can move in the axial direction.

The sticking needle 4 has a needle body 41 and a hub 42 fixed to theproximal end of the needle body 41.

The needle body 41 is a hollow or solid member made of a metallicmaterial, such as stainless steel, aluminum, aluminum alloy, titanium,and titanium alloy. It has a sharp needle point, which sticks into theskin of the fingertip F, thereby causing the blood to bleed.

To the proximal end of the needle body 41 is fixed the hub 42 bywelding, bonding (with an adhesive), fitting, or staking.

The hub 42 is an approximately cylindrical member, with its outersurface sliding on the inside of the casing 3.

At the proximal end of the hub 42 is formed a fitting part 421, whichfits into the needle holder 411 of the plunger 410 (sticking means 400)when the body fluid collecting device 1 is mounted on the componentmeasuring apparatus 100.

The casing 3 is a cylindrical member having an opening 31 at its distalend and an opening 32 at its proximal end. The needle body 41 passesthrough the distal opening 31 to project from the distal end of the bodyfluid collecting device 1.

The casing 3 has a decreased inside diameter in its distal part, so thatthe end surface 422 of the hub 42 comes into contact with the insidesurface 33 as the sticking needle 4 moves in the distal direction. Thisstructure regulates the maximum length of projection of the needle body41 from the distal end of the body fluid collecting device 1. Thus, theneedle point of the needle body 41 does not stick the fingertip F deeperthan necessary when the sticking needle 4 sticks the surface of thefingertip F.

On the other hand, the casing 3 has an approximately constant insidediameter in its part close to the proximal end, and is slightly largerthan the maximum outside diameter of the hub 42. This structure permitsthe sticking needle 4 to move smoothly in the axial direction of thehousing 3.

The casing 3 has on its inside (close to the proximal end) a ring-shapedridge 34 projecting inward. The ridge 34 engages with the outerperiphery of the hub 42 when the body fluid collecting device 1 is notin use (as shown in FIG. 3), so that the sticking needle 4 is fixed tothe casing 3. In this state, the needle point of the needle body 41 doesnot project from the distal opening 31.

The hub 42 fits into the ridge 34 with an adequate force which is strongenough for the fitting part 421 of the sticking needle 4 to smoothly fitinto the needle holder 411 but weak enough for the hub 42 to easilydisengage from the ridge 34 when the sticking means 400 is actuated.

Incidentally, there are no restrictions in the method of fixing the hub42 to the casing 3. Other methods may be used, for example, by attachingengaging means to the inside of the casing 3 and/or the outside of thehub 42; by using friction between the inside of the casing 3 and theoutside of the hub 42; by weakly bonding or welding together the casing3 and the hub 42.

The fitting between the hub 42 and the inside undercut (or the ridge 34)of the casing 3 blocks entrance of bacteria into the needleaccommodating section 2. Therefore, the sticking needle 4 remainssterilized until the body fluid collecting device 1 is used once theneedle accommodating section 2 is sterilized.

There is a step 35 on the outside of the casing 3 at an intermediatepoint in the lengthwise direction. The sensor holder 6 is fitted to thepart (fitting part 36) extending distally from this step 35. When thesensor holder 6 is fitted to the fitting part 36 (as shown in FIGS. 1and 3), the proximal end of the sensor holder 6 comes into contact withthe step 35, so that the sensor holder 6 is properly positioned (in thelengthwise direction) with respect to the casing 3 (the needleaccommodating section 2). In other words, the step 35 determines theposition of the sensor holder 6 (in the lengthwise direction) withrespect to the needle accommodating section 2. The state as shown inFIGS. 1 and 3 is referred to as “the assembled state of the body fluidcollecting device 1”.

The position determining means mentioned above accurately controls howfar the needle body 41 projects from the body fluid collecting device 1,thereby preventing the needle from sticking into the fingertipunnecessarily deep.

There are a pair of grooves 37 (facing each other) extending in thelengthwise direction on the outside of the casing 3. These grooves 37function as nonslip means when a user grips the body fluid collectingdevice 1, so help the user to firmly grip the body fluid collectingdevice 1 by fingers.

The sensor 5 is intended to determine specific components in blood. Inother words, upon contact with blood (or body fluid), it electricallymeasures (or detects) the blood glucose level.

In this embodiment, the sensor 5 should preferably be made of plastics,such as polyethylene terephthalate and polystyrene, so that it bends orcurves in the non-contact space 64 mentioned later. The sensor 5 has, atthe center of the distal end, a measuring part 51 which is 0.5 to 4.0 mmwide, 1.0 to 10.0 mm long, and 0.01 to 1.0 mm thick. The measuring part51 is so constructed as to hold therein blood (body fluid) by capillaryphenomenon, and it contains reagents to react with glucose (prescribedcomponent) in blood.

The sensor 5 also has, on its upper-side, a pair of electrodes 52 a and52 b in the form of thin film, as shown in FIG. 2. These electrodes havetheir distal ends positioned on the measuring part 51.

When the body fluid collecting device 1 is mounted on the componentmeasuring apparatus 100, the contact points 731 and 732 of the measuringmeans 700 are in contact with (and electrically connected to) theelectrodes 52 a and 52 b, respectively, so that voltage is applied tothe measuring part 51 through the electrodes 52 a and 52 b.

The reagents used for determination include at least one species ofoxidoreductases (such as glucose oxidase and glucose dehydrogenase) andat least one species of electron acceptors (such as potassiumferricyanide, ferrocene derivative, quinone derivatives, and metalcomplexes).

The determination of blood glucose level is based on the principle whichis explained in the following. It is assumed that the reagent used fordetermination is a combination of glucose oxidase (GOD) and potassiumferricyanide (K₃[Fe_((III))(CN)₆]).

When blood enters the measuring part 51, glucose in the bloodspecifically reacts with GOD to evolve gluconic acid and electrons.Then, these electrons convert (reduce) the potassium ferricyanide(K₃[Fe_((III))(CN)₆]) into potassium ferrocyanide (K₄[Fe_((II))(CN)₆]).The potassium ferrocyanide is restored (oxidized) again to potassiumferricyanide by voltage applied from the measuring means 700. At thistime, current occurs. The amount of this current is proportional to theamount of glucose; therefore, it is possible to calculate the bloodglucose level by measuring (detecting) the change in current from thesensor 5 with the help of the measuring means 700.

The sensor 5 mentioned above is held between the needle accommodatingpart 2 and the sensor holder 6. The sensor holder 6 is mounted on thedistal end of the needle accommodating part 2. (The distal end is themounting part 36 of the casing 3.) The sensor holder 6 has a pair ofside walls 61 and 61 facing each other and a top plate 62 (whichconnects the side walls and has a U-shaped cross section).

On the inside of each side wall 61 is formed a groove 611 extending inthe lengthwise direction. When the body fluid collecting device 1 isassembled, both sides of the mounting part 36 of the casing 3 fit intothese grooves 611, so that the sensor holder 6 is fixed to the needleaccommodating part 2.

The sensor holder 6 and the casing 3 (the needle accommodating part 2)are in contact with each other through flat surfaces, so that the flatsensor 5 is held (supported) stably and firmly.

In addition, when the body fluid collecting device 1 is assembled, theproximal end of the sensor 5 is held between the top of the mountingpart 36 of the casing 3 and the inside (or the lower side) 621 of thetop plate 62. This simple structure firmly fixes the sensor 5, and hencethe body fluid collecting device 1 can be assembled very easily. In thisembodiment (in which the body fluid collecting device has the stickingneedle integral therewith), there is a second supporter 82 that supportsthe proximal end of the sensor 5. Inside the distal end of the sensorholder 6 is a first supporter 81 that supports the vicinity of themeasuring part 51 of the sensor 5.

In other words, the body fluid collecting device 1 has a first supporter81 (which supports the vicinity of the measuring part 51 of the sensor5) and a second supporter 82 (which supports the sensor 5 at its partcloser to the proximal side than the first supporter 81).

At the distal end of the sensor holder 6 is formed a blood (body fluid)duct 63 communicating with the first supporter 81. This blood duct 63collects blood bleeding from the fingertip F at which the stickingneedle 4 has been stuck, and then it introduces the collected blood tothe distal end (the measuring part 51) of the sensor 5 supported by thefirst supporter 81.

The blood duct 63 is a thin orifice, which has an opening 631 at itsdistal end (from which blood enters) and an opening 632 at its proximalend (from which blood leaves). Blood is fed to the measuring part 51through the blood duct 63 by capillary phenomenon.

The blood duct 63 that relies on capillary phenomenon should haveadequate dimensions (especially, an adequate ratio of length to insidediameter).

To be concrete, the length (indicated by L in FIG. 4) of the blood duct63 should be about 0.1 to 10 mm, preferably about 0.5 to 5 mm, althoughit is not specifically restricted. Also, the inside diameter (indicatedby D in FIG. 4) should be about 0.1 to 3 mm, preferably about 0.5 to 1.5mm, although it is not specifically restricted.

The volume of the blood duct 63 should be about 0.5 to 2 times,preferably 0.8 to 1.5 times, the volume of the measuring part 51 of thesensor 5, although it is not specifically restricted. Specifying thevolume of the blood duct 63 based on the volume of the measuring part 51makes it possible to reduce the amount of blood to be collected. As theresult, the amount of bleeding from the stuck point of the fingertip Fis reduced and hence the patient's strain is also reduced. Moreover, ifthe amount of blood is not enough to fill the blood duct 63, blood doesnot come into contact with the measuring part 51. This avoids failure inmeasurement due to insufficient blood sample.

The first supporter 81 mentioned above is placed nearer the central axisof the sticking needle 4 than the second supporter 82 mentioned above.The advantage of arranging the first and second supporters 81 and 82 inthis manner is that the sensor 5 is bent or curved in the non-contactspace 64 mentioned later (which is between the first supporter 81 andthe second supporter 82). In other words, the distal end of the sensor 5is bent (or inclined) toward the central axis of the sticking needle 4,and hence the measuring part 51 of the sensor 5 is arranged aslant withrespect to the lengthwise direction of the blood duct 63. Moreover, withthe distal end of the sensor 5 bent or inclined toward the central axisof the sticking needle 4, the sensor 5 is firmly fixed by the first andsecond supporters 81 and 82, and the distal end of the sensor 5 isbrought close to the sticking position.

Also, as mentioned above, the vicinity of the measuring part 51 of thesensor 5 is supported by the first supporter 81 and the measuring part51 is placed near the vicinity of the opening 632 (for outlet) of theblood duct 63.

Arrangement in this manner offers the advantage that the bloodintroduced through the blood duct 63 is efficiently fed into themeasuring part 51 and hence the blood glucose level can be measured witha less amount of blood sample.

Especially, the body fluid collecting device 1 mentioned above has anon-contact space 64 (in which the surface of the sensor 5 does not comeinto contact with the inside of the sensor holder 6) between the firstsupporter 81 and the second supporter 82. The volume of the non-contactspace 64 is larger than that of the space demarcated by the firstsupporter 81. Thus, the blood introduced through the blood duct 63 bycapillary phenomenon reaches the first supporter 81 but its movementtoward the proximal end is prevented. As the result, the collected bloodstays in the first supporter 81 and is supplied to the measuring part 51efficiently (without waste). This leads to reduction in the amount ofblood to be collected.

In this embodiment, the non-contact space 64 prevents blood (body fluid)from infiltrating into any other part than the measuring part 51 of thesensor 5.

In addition, above the proximal end of the first supporter 81 is formeda concave 811 that communicates with the non-contact space 64. In thisembodiment, this concave 811 is formed by partly cutting out the firstsupporter 81, as shown in FIG. 4. The concave (notch) 811 certainlyprevents blood from infiltrating into the proximal end of the sensor 5along the upper lateral side of the sensor 5.

Incidentally, the means to prevent infiltration of blood (or body fluid)does not necessarily to be the non-contact space 64 formed between thefirst supporter 81 and the second supporter 82. The same object will beachieved by making water-repellent the vicinity of the proximal end ofthe first supporter 81.

At the end of the sensor holder 6 is formed a guide 7 (which projectsfrom the end). This guide 7 efficiently introduces blood into theopening (inlet) 631 of the blood duct 63. It has a plurality of legs.(Two legs 71 a and 71 b are shown in FIG. 4.)

The legs 71 a and 71 b extend from the vicinity of the opening (inlet)631 of the blood duct 63 toward the central axis of the sticking needle4. In addition, the legs 71 a and 71 b gradually separate from eachother as they extend toward the central axis.

In other words, the legs 71 a and 71 b are so arranged as to inclineinward, but they do not join together at their lower ends (as shown inFIG. 1). Therefore, they do not clog the blood duct 63 (or the internalspace of the guide 7) when the distal end of the guide 7 is brought intocontact with the skin of the fingertip F for blood collection. That is,they secure the passage for blood, thereby ensuring smooth supply ofblood to the measuring part 51.

Incidentally, the number of legs is not limited to the one shown in thefigure; it may be three or more.

The distance from the distal end of the guide 7 to the opening (inlet)631 of the blood duct 63 should preferably be about 0.1 to 10 mm, morepreferably about 0.2 to 3 mm. (The distance is indicated by “A” in FIG.3.) The thus specified length (A) is necessary for a small amount ofblood to be introduced efficiently into the opening (inlet) 631 of theblood duct 63.

The guide 7 should preferably be hydrophilicized, so that it rapidlyintroduces blood into the opening (inlet) 631 of the blood duct 63.

Hydrophilicizing may be accomplished by physical activation such asozone treatment, plasma treatment, glow discharge, corona discharge, andUV light irradiation, or by chemical coating with any of surfactant,water-soluble silicone, hydroxypropyl cellulose, polyethylene glycol,polypropylene glycol, and the like.

Alternatively, the guide 7 itself may be formed from a highlyhydrophilic material such as acrylic resin.

Such hydrophilicizing as mentioned above may also be applied to otherparts (e.g., the inside of the first supporter 81) of the body fluidcollecting device 1.

The sensor holder 6 (or the body fluid collecting device 1) has itsdistal end made substantially transparent (colorless, colored, ortranslucent), so that the user (or patient) can watch (from outside ofthe body fluid collecting device 1) blood being fed to the measuringpart 51 through the blood duct 63. This permits the user (or patient) tofeel easy. Moreover, in this way it is possible to avoid failure inmeasurements (or incorrect measurement) due to insufficient bloodcollection (or malfunction of blood introduction into the blood duct63).

The sensor holder 6 (or the top plate 62) has a notch 622 formed at itsproximal end. When the body fluid collecting device 1 is assembled, thenotch 622 permits the proximal end of the electrodes 52 a and 52 b ofthe sensor 5 to be exposed to the outside of the body fluid collectingdevice 1.

When the body fluid collecting device 1 is mounted on the componentmeasuring apparatus 100 (or the housing 500), the contact points 731 and732 advances into the notch 622, so that a part of their vertices comeinto contact with the electrodes 52 a and 52 b.

The step 35 of the needle accommodating part 2 (or the casing 3) has aninclined plane 351 formed at the position corresponding to the notch622. The inclined plane 351 permits the contact points 731 and 732 toadvance into and retract from the notch 622 smoothly when the body fluidcollecting device 1 is mounted and dismounted on and from the componentmeasuring apparatus 100.

The sensor holder 6, casing 3, and hub 42 mentioned above shouldpreferably be made of plastics. Examples of the plastics include ABSresin, AS resin, polyethylene, polypropylene, polystyrene, polyvinylchloride, polyvinylidene chloride resin, polyphenylene oxide,thermoplastic polyurethane, polymethyl methacrylate, polyoxyethylene,fluorocarbon resin, polycarbonate, polyamide, acetal resin, acrylicresin, polyethylene terephthalate, and other thermoplastic resins (whichare capable of injection molding), and phenolic resin, epoxy resin,silicone resin, unsaturated polyester resin, and other thermosettingresins.

The body fluid collecting device 1 is assembled after the needleaccommodating part 2 has been sterilized with ethylene oxide gas (EOG)or the like. In this embodiment, the needle accommodating part 2 issterilized after sealing the distal opening 31 of the casing 3 with amembrane 91 which permits gas permeation but prevents the passage ofbacteria.

In the proximal part of the needle accommodating part 2 before the bodyfluid collecting device 1 is in use, the peripheral part of the hub 42fits into the ridge 34 and the sticking needle 4 is fixed to the casing3, as mentioned above. The fitting part allows the passage of gas to acertain degree but prevents the passage of bacteria. Therefore, if thedistal opening 31 of the casing 3 is sealed with a membrane (filter) 91and then sterilization is performed, the inside of the needleaccommodating part 2 remains sterilized until the body fluid collectingdevice 1 is put to use.

The membrane 91 (as shown in FIG. 3) is unsealed as it is pierced by theneedle point of the needle body 41 when the sticking needle 4 sticks thefingertip F.

The sealing member may be constructed differently as explained laterwith reference to FIGS. 5 and 6.

The sealing member shown in FIG. 5 is the membrane 92, which isidentical with the membrane mentioned above. It has one end 921 thereoffixed to the lid 11 of the case 10 which accommodates the body fluidcollecting device 1. To be concrete, one end 921 of the membrane 92 isheld (and fixed) between the lid 11 and the internal member 12 placed inthe lid 11. Therefore, as soon as the lid 11 of the case 10 is removed,the membrane 92 peels off from the needle accommodating part 2 to openit.

The sealing member shown in FIG. 6 is the pin 93, with its one end 931fitting into the distal opening 31 of the casing 3. FIG. 6 shows thebody fluid collecting device 1 which has been assembled aftersterilization of the needle accommodating part 2 with its end closed.

When the body fluid collecting device 1 is accommodated in the case 10,the fitting part 932, which is formed at another end of the pin 93, fitsinto the hole 11 a which is formed inside the lid 11.

The lid 11 fits into the case 10 with a larger force than the pin 93fits into the distal opening 31 of the casing 3. Therefore, as soon asthe lid 11 is removed, the pin 93 releases itself from the needleaccommodating part 2 to open it.

The body fluid collecting device 1 mentioned above assumes approximatelya rectangular solid as shown in FIGS. 1 and 2. Therefore, it does notroll about on the table before and after its use, and there is nopossibility of blood being scattered after blood collection.

When the body fluid collecting device 1 is mounted on the componentmeasuring apparatus 100, its distal end projects from the apparatus 100as shown in FIG. 10. To use it, the distal end of the guide 7 is broughtinto contact with the surface (skin) of the fingertip F and then thesticking needle 4 sticks the surface of the fingertip F. The body fluidcollecting device 1 used in this manner permits the user to establishthe reference position that regulates the depth the sticking needle 4reaches when it sticks into the fingertip F (or the length over whichthe needle body 41 projects). By using the distal end of the body fluidcollecting device 1 as the reference position in this manner, it ispossible to ensure uniform sticking into the fingertip F by the stickingneedle 4. The foregoing structure permits the sticking needle 4 to stickthe fingertip F in the neighborhood of the guide 7. Thus the guide 7captures blood advantageously.

In addition, since the body fluid collecting device 1 has the stickingneedle 4 and the sensor 5, as mentioned above, it is capable ofcontinuous operation: needle sticking, blood collection, blood supply tothe sensor 5, and determination of components. This facilitates easy andrapid measurements of blood glucose level. Moreover, the componentmeasuring apparatus 100 merely needs simple preparatory operation, andthis facilitates periodic use or repeated use. The body fluid collectingdevice 1 mentioned above is suitable for measurements of blood glucoselevel by the patient oneself. It is simple in structure, inexpensive,and suitable for mass production. A description is given below of themethod for using the body fluid collecting device 1 mounted on thecomponent measuring apparatus 100.

[1] First, the body fluid collecting device 1 is mounted on (insertedinto) the mounting part 530 of the housing 500 through the opening 212of the casing 210, so that the fitting part 421 of the sticking needle 4fits on the needle holder 411.

The body fluid collecting device 1 is pushed further toward the proximalend, so that the plunger 410 is moved toward the proximal end againstthe urging force of the coil spring 420. In the initial state, a part inthe vicinity of the vertex of the locking part 413 is kept in contactwith the inside of the housing 500 by the elastic force of the elasticpiece 412. As soon as the locking part 413 reaches the position of theopening 570, it projects into the opening 570, as shown in FIG. 10. Inthis state, the locking part 413 is caught by the edge of the opening570 even after the removal of force to press the plunger 410 toward theproximal end by the body fluid collecting device 1. Thus, the plunger410 is kept from moving toward the distal end. In this state, the coilspring 420 is compressed. Now, the procedure for sticking and bloodcollection by the sticking means 400 is ready to start.

In this stage, the contact points 731 and 732 of the measuring means 700advance into the notch 622 of the sensor holder 6, so that they comeinto contact with the electrodes 52 a and 52 b of the sensor 5,respectively. In this way the sensor 5 is electrically connected to themeasuring means 700.

[2] Then, the power switch (not shown) is turned on, so that thecomponent measuring apparatus 100 is activated for measuring operation.

[3] The patient presses his fingertip F against the distal end of theguide 7 (or the distal end of the body fluid collecting device 1), asshown in FIG. 10. While keeping this state, the patient depresses thecontrol button 222 to activate the component measuring apparatus 100.

With the control button 222 depressed, the unlocking part 223 moves inthe direction of arrow as shown in FIG. 10. It comes into contact withthe locking part 413 and depresses it back into the internal space 520of the housing 500. Thus, the locking part 413 is disengaged, and theplunger 410 is moved toward the distal end by the elastic force of thecoil spring 420 (which has been compressed). The movement of the plunger410 toward the distal end causes the sticking needle 4 to move towardthe distal end, so that the needle point of the needle body 41 piercesthe membrane 91, passes through the distal opening 31, projects from thedistal end of the body fluid collecting device 1, and sticks into theskin of the fingertip F.

After that the coil spring 430 pushes back the plunger 410 toward theproximal end. The plunger 410 reciprocates (or repeatedly moves towardthe distal end and toward the proximal) due to elastic force applied bythe coil springs 420 and 430. It eventually comes to rest at a positionwhere the force of the coil spring 420 balances with that of the coilspring 430. In this stage, the needle point of the needle body 41 isaccommodated in the body fluid collecting device 1. In other words, thebody fluid collecting device 1 is so designed as to prevent the needlepoint of the needle body 41 from projecting from its distal end while itis not in use. Thus, it is quite safe to use without possibility ofinadvertent injury and infection to the skin.

[4] The component measuring apparatus 100, with the body fluidcollecting device 1 mounted thereon, is placed on a desk temporarily.Using his fingers, the patient kneads that part of the fingertip F whichhas been stuck by the sticking needle 4 so as to assist bleeding.

This step, however, may be omitted unless it is necessary.

[5] Holding the component measuring apparatus 100 again, the patientbrings the guide 7 of the body fluid collecting device 1 into contactwith the blood forming a small drop at that part of the fingertip wherethe needle has been stuck in the step [4] mentioned above.

In this step, the guide 7 introduces the blood into the opening (inlet)631 of the blood duct 63. The blood passes through the blood duct 63 andreaches the measuring part 51 of the sensor 5 due to capillaryphenomenon.

In the measuring part 51, glucose in the blood reacts with the reagents,thereby generating electric current in proportion to the amount ofglucose.

[6] The control means 111 measures, with the measuring means 700, thechange in current from the sensor 5 and performs arithmetic operationsaccording to the thus obtained data. After temperature and hematocritcorrections, it determines the blood glucose level.

The thus calculated blood glucose level is displayed on the display unit112, so that the patient can know his own blood glucose level.

The foregoing procedure makes it possible to rapidly and surely collectblood necessary and sufficient for measurement and to accuratelydetermine the blood glucose level (or the amount of a specific componentin blood) with a less amount of blood.

Second Embodiment

The second embodiment of the present invention covers another body fluidcollecting device which is integral with the sticking needle.

FIG. 7 is a longitudinal sectional view showing the distal end of thebody fluid collecting device in the second embodiment of the presentinvention. Incidentally, the following conventions are adopted.“Proximal end” and “distal end” represent respectively the right sideand the left side in FIG. 7.

The following describes the difference between the body fluid collectingdevice 1 in the second embodiment (shown in FIG. 7) and that in thefirst embodiment, without describing those items common to them.

The body fluid collecting device 1 in the second embodiment is identicalwith that in the first embodiment except that the guide 7 differs inshape.

In the second embodiment, the guide 7 consists of a capillary tube 72having an internal space 721 communicating with the blood duct 63. Thedistal end of the guide 7 serves as a reference for contact with blood.It facilitate the step [5] mentioned above, while surely preventing theloss of blood which otherwise would occur because blood adheres to otherparts than the guide 7 when the distal end of the guide 7 is broughtinto contact with the blood drop at the sticking point.

At the distal end of the capillary tube 72 is formed a groove 722communicating with the internal space 721 (blood duct 63). The grooveshown in FIG. 7 is a straight one extending in the radial direction ofthe capillary tube 72, and its both ends are open to the externalperiphery of the capillary tube 72.

The groove 722 prevents the internal space 721 of the capillary tube 72(blood duct 63) from being clogged when the distal end of the capillarytube 72 (guide 7) is brought into contact with the skin of the fingertipF for blood collection, thereby ensuring the passage of blood and thesmooth supply of blood to the blood measuring part 51.

The depth of the groove 722 varies depending on the surface state of thefingertip F without specific restrictions. However, it is usually nosmaller than 0.1 mm, preferably from 0.2 to 1.8 mm. With an excessivelyshallow depth, the groove 722 will not permit blood to pass sufficientlythrough the internal space 721 when the distal end of the guide isstrongly pressed against the skin of the fingertip F.

The groove 722 is not restricted in shape, number, and arrangement tothe shown one. It may be constructed in such a way that when the distalend of the capillary tube 72 is brought into contact with the skin ofthe fingertip F, part of it remains free. In other words, more than onegroove 722 (in an X-shaped pattern) radiating from the central axis ofthe capillary tube may be formed.

The body fluid collecting device constructed in this manner produces thesame effect as that in the first embodiment.

Although the invention has been described in its preferred form (bodyfluid collecting devices illustrated above), it is to be understood thatthe invention is not limited to such specific embodiments but eachconstituent will be replaced by any one which produces the same effect.It goes without saying that the body fluid collecting device accordingto the present invention will fully produce its effect even though it isnot provided with the sticking needle or the needle accommodating part.

To be concrete, the sticking needle used for the body fluid collectingdevice of the present invention may be replaced by another one (such asa syringe) for blood collection. Even in such a case, the present bodyfluid collecting device has the first supporter 81 and the secondsupporter 82 (which is closer to the proximal end than the firstsupporter 81) such that they form a non-contact space 64 between them inwhich the surface of the sensor 5 is substantially not in contact withthe inside of the sensor holder 6, and the volume of the non-contactspace 64 is larger than that of the space demarcated by the firstsupporter 81. Therefore, the blood reaches the first supporter 81 butdoes not move further toward the proximal end. Thus, the collected bloodis retained in the first supporter 81 and then supplied to the measuringpart 51 efficiently without any loss. This makes it possible to reducethe amount of blood to be collected.

In the one provided with the guide 7 and the blood duct 63, blood passesthrough the blood duct 63 due to capillary phenomenon and efficientlyreaches the measuring part 51 which is aslant with respect to thelengthwise direction of the blood duct 63. This makes it possible toreduce the amount of blood to be collected.

According to the present invention, two or more constructions in theabove-mentioned embodiments may be properly combined with each other.

The embodiments mentioned above are designed on the assumption that thebody fluid to be collected is blood. However, the body fluid to becollected is not limited to blood. The body fluid may include urine,sweat, lymph, spinal fluid, bile, and saliva.

In addition, the embodiments mentioned above are designed on theassumption that the component to be determined is glucose (blood glucoselevel). However, the component for measurement is not limited toglucose; it includes, for example, alcohols, sugars, cholesterol, lacticacid, vitamins, hemoglobin, uric acid, creatinine, proteins, andinorganic ions (such as sodium).

The reagent in the sensor contains an oxidoreductase, which may beselected from alcohol oxidase, alcohol dehydrogenase, galactose oxidase,fructose dehydrogenase, cholesterol oxidase, cholesterol dehydrogenase,lactic acid oxidase, lactic acid dehydrogenase, ascorbic acid oxidase,bilirubin oxidase, and xanthine oxidase.

In the above-mentioned embodiments, the sensor is intended to determinethe amount of specific components. However, it may also be intended forqualitative and/or quantitative analysis of specific components.

The sensor should preferably be so designed as to carry out analysiselectrically by means of the above-mentioned reagents. However, analysiswith an optical or any other means may also be adopted.

INDUSTRIAL APPLICABILITY

As mentioned above, the present invention produces the followingeffects.

The body fluid collecting device permits the user to collect body fluideasily and detects specific components in body fluid with a small amountof sample.

The body fluid collecting device is easy to assemble and is capable ofeasily controlling the depth of sticking. Moreover, it surely detectsprescribed components in body fluid.

The body fluid collecting device is provided with a sticking needle sothat it can perform in succession sticking, body fluid collection,supply of body fluid to the sensor, and detection of prescribedcomponents. Therefore, it can easily and rapidly detect prescribedcomponents. It can be easily made ready for use, which is advantageousfor periodic use and repeated use.

The body fluid collecting device prevents inadvertent accidents, such assticking twice the skin of the fingertip, and hence it is safe to use.

Therefore, the body fluid collecting device according to the presentinvention is suitable for determination of blood glucose level by thepatient himself. It is simple in structure, inexpensive, and suitablefor mass production.

1. A body fluid collecting device including a sensor to detect aprescribed component in the body fluid, wherein said sensor includes atits distal end a measuring part capable of holding said body fluid, saidbody fluid collecting device includes a first supporter to support thevicinity of said measuring part of said sensor and a second supporter tosupport said sensor at a place closer to the proximal end than saidfirst supporter, with said first and second supporters forming betweenthem a non-contact space in which the surface of said sensor does notsubstantially come into contact with the inside of said body fluidcollecting device, and said first supporter has at its proximal end aconcave that communicates with said non-contact space.
 2. The body fluidcollecting device as defined in claim 1, wherein said concave is a notchformed by cutting part of said first supporter.
 3. The body fluidcollecting device as defined in claim 1, wherein said sensor is bent orcurved in said non-contact space.
 4. The body fluid collecting device asdefined in claim 1, wherein said first supporter is arranged closer tothe central axis of said body fluid collecting device than said secondsupporter.
 5. The body fluid collecting device as defined in claim 1,wherein said sensor electrically detects the prescribed component in thebody fluid by contact with said body fluid.
 6. The body fluid collectingdevice as defined in claim 1, which further includes a body fluid ductwhich communicates with said first supporter and introduces said bodyfluid into said measuring part.
 7. The body fluid collecting device asdefined in claim 6, wherein said body fluid duct has a volume which is0.5 to 2 times the volume of said measuring part.
 8. The body fluidcollecting device as defined in claim 6, wherein said body fluid duct is0.1 to 10 mm in length and 0.1 to 3 mm in inside diameter.
 9. The bodyfluid collecting device as defined in claim 6, wherein said measuringpart is inclined with respect to the lengthwise direction of said bodyfluid duct and is positioned in the vicinity of the outlet opening ofsaid body fluid duct.
 10. The body fluid collecting device as defined inclaim 6, which further includes a guide that projects from the distalend of said body fluid collecting device and introduces said body fluidinto the inlet opening of said body fluid duct, said guide being formedsuch that the distance from the distal end thereof to the inlet openingof said body fluid duct is 1 to 10 mm.